includes/WatchedItemStore.php

   1 <?php
   2
   3 use Wikimedia\Assert\Assert;
   4
   5 /**
   6  * Storage layer class for WatchedItems.
   7  * Database interaction.
   8  *
   9  * @author Addshore
  10  *
  11  * @since 1.27
  12  */
  13 class WatchedItemStore {
  14
  15         /**
  16          * @var LoadBalancer
  17          */
  18         private $loadBalancer;
  19
  20         /**
  21          * @var HashBagOStuff
  22          */
  23         private $cache;
  24
  25         /**
  26          * @var array[] Looks like $cacheIndex[Namespace ID][Target DB Key][User Id] => 'key'
  27          * The index is needed so that on mass changes all relevant items can be un-cached.
  28          * For example: Clearing a users watchlist of all items or updating notification timestamps
  29          *              for all users watching a single target.
  30          */
  31         private $cacheIndex = [];
  32
  33         /**
  34          * @var callable|null
  35          */
  36         private $deferredUpdatesAddCallableUpdateCallback;
  37
  38         /**
  39          * @var callable|null
  40          */
  41         private $revisionGetTimestampFromIdCallback;
  42
  43         /**
  44          * @var self|null
  45          */
  46         private static $instance;
  47
  48         /**
  49          * @param LoadBalancer $loadBalancer
  50          * @param HashBagOStuff $cache
  51          */
  52         public function __construct(
  53                 LoadBalancer $loadBalancer,
  54                 HashBagOStuff $cache
  55         ) {
  56                 $this->loadBalancer = $loadBalancer;
  57                 $this->cache = $cache;
  58                 $this->deferredUpdatesAddCallableUpdateCallback = [ 'DeferredUpdates', 'addCallableUpdate' ];
  59                 $this->revisionGetTimestampFromIdCallback = [ 'Revision', 'getTimestampFromId' ];
  60         }
  61
  62         /**
  63          * Overrides the DeferredUpdates::addCallableUpdate callback
  64          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  65          *
  66          * @param callable $callback
  67          *
  68          * @see DeferredUpdates::addCallableUpdate for callback signiture
  69          *
  70          * @return ScopedCallback to reset the overridden value
  71          * @throws MWException
  72          */
  73         public function overrideDeferredUpdatesAddCallableUpdateCallback( $callback ) {
  74                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  75                         throw new MWException(
  76                                 'Cannot override DeferredUpdates::addCallableUpdate callback in operation.'
  77                         );
  78                 }
  79                 Assert::parameterType( 'callable', $callback, '$callback' );
  80
  81                 $previousValue = $this->deferredUpdatesAddCallableUpdateCallback;
  82                 $this->deferredUpdatesAddCallableUpdateCallback = $callback;
  83                 return new ScopedCallback( function() use ( $previousValue ) {
  84                         $this->deferredUpdatesAddCallableUpdateCallback = $previousValue;
  85                 } );
  86         }
  87
  88         /**
  89          * Overrides the Revision::getTimestampFromId callback
  90          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
  91          *
  92          * @param callable $callback
  93          * @see Revision::getTimestampFromId for callback signiture
  94          *
  95          * @return ScopedCallback to reset the overridden value
  96          * @throws MWException
  97          */
  98         public function overrideRevisionGetTimestampFromIdCallback( $callback ) {
  99                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 100                         throw new MWException(
 101                                 'Cannot override Revision::getTimestampFromId callback in operation.'
 102                         );
 103                 }
 104                 Assert::parameterType( 'callable', $callback, '$callback' );
 105
 106                 $previousValue = $this->revisionGetTimestampFromIdCallback;
 107                 $this->revisionGetTimestampFromIdCallback = $callback;
 108                 return new ScopedCallback( function() use ( $previousValue ) {
 109                         $this->revisionGetTimestampFromIdCallback = $previousValue;
 110                 } );
 111         }
 112
 113         /**
 114          * Overrides the default instance of this class
 115          * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined.
 116          *
 117          * If this method is used it MUST also be called with null after a test to ensure a new
 118          * default instance is created next time getDefaultInstance is called.
 119          *
 120          * @param WatchedItemStore|null $store
 121          *
 122          * @return ScopedCallback to reset the overridden value
 123          * @throws MWException
 124          */
 125         public static function overrideDefaultInstance( WatchedItemStore $store = null ) {
 126                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
 127                         throw new MWException(
 128                                 'Cannot override ' . __CLASS__ . 'default instance in operation.'
 129                         );
 130                 }
 131
 132                 $previousValue = self::$instance;
 133                 self::$instance = $store;
 134                 return new ScopedCallback( function() use ( $previousValue ) {
 135                         self::$instance = $previousValue;
 136                 } );
 137         }
 138
 139         /**
 140          * @return self
 141          */
 142         public static function getDefaultInstance() {
 143                 if ( !self::$instance ) {
 144                         self::$instance = new self(
 145                                 wfGetLB(),
 146                                 new HashBagOStuff( [ 'maxKeys' => 100 ] )
 147                         );
 148                 }
 149                 return self::$instance;
 150         }
 151
 152         private function getCacheKey( User $user, LinkTarget $target ) {
 153                 return $this->cache->makeKey(
 154                         (string)$target->getNamespace(),
 155                         $target->getDBkey(),
 156                         (string)$user->getId()
 157                 );
 158         }
 159
 160         private function cache( WatchedItem $item ) {
 161                 $user = $item->getUser();
 162                 $target = $item->getLinkTarget();
 163                 $key = $this->getCacheKey( $user, $target );
 164                 $this->cache->set( $key, $item );
 165                 $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] = $key;
 166         }
 167
 168         private function uncache( User $user, LinkTarget $target ) {
 169                 $this->cache->delete( $this->getCacheKey( $user, $target ) );
 170                 unset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()][$user->getId()] );
 171         }
 172
 173         private function uncacheLinkTarget( LinkTarget $target ) {
 174                 if ( !isset( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] ) ) {
 175                         return;
 176                 }
 177                 foreach ( $this->cacheIndex[$target->getNamespace()][$target->getDBkey()] as $key ) {
 178                         $this->cache->delete( $key );
 179                 }
 180         }
 181
 182         /**
 183          * @param User $user
 184          * @param LinkTarget $target
 185          *
 186          * @return WatchedItem|null
 187          */
 188         private function getCached( User $user, LinkTarget $target ) {
 189                 return $this->cache->get( $this->getCacheKey( $user, $target ) );
 190         }
 191
 192         /**
 193          * Return an array of conditions to select or update the appropriate database
 194          * row.
 195          *
 196          * @param User $user
 197          * @param LinkTarget $target
 198          *
 199          * @return array
 200          */
 201         private function dbCond( User $user, LinkTarget $target ) {
 202                 return [
 203                         'wl_user' => $user->getId(),
 204                         'wl_namespace' => $target->getNamespace(),
 205                         'wl_title' => $target->getDBkey(),
 206                 ];
 207         }
 208
 209         /**
 210          * @param int $slaveOrMaster DB_MASTER or DB_SLAVE
 211          *
 212          * @return DatabaseBase
 213          * @throws MWException
 214          */
 215         private function getConnection( $slaveOrMaster ) {
 216                 return $this->loadBalancer->getConnection( $slaveOrMaster, [ 'watchlist' ] );
 217         }
 218
 219         /**
 220          * @param DatabaseBase $connection
 221          *
 222          * @throws MWException
 223          */
 224         private function reuseConnection( $connection ) {
 225                 $this->loadBalancer->reuseConnection( $connection );
 226         }
 227
 228         /**
 229          * Count the number of individual items that are watched by the user.
 230          * If a subject and corresponding talk page are watched this will return 2.
 231          *
 232          * @param User $user
 233          *
 234          * @return int
 235          */
 236         public function countWatchedItems( User $user ) {
 237                 $dbr = $this->getConnection( DB_SLAVE );
 238                 $return = (int)$dbr->selectField(
 239                         'watchlist',
 240                         'COUNT(*)',
 241                         [
 242                                 'wl_user' => $user->getId()
 243                         ],
 244                         __METHOD__
 245                 );
 246                 $this->reuseConnection( $dbr );
 247
 248                 return $return;
 249         }
 250
 251         /**
 252          * @param LinkTarget $target
 253          *
 254          * @return int
 255          */
 256         public function countWatchers( LinkTarget $target ) {
 257                 $dbr = $this->getConnection( DB_SLAVE );
 258                 $return = (int)$dbr->selectField(
 259                         'watchlist',
 260                         'COUNT(*)',
 261                         [
 262                                 'wl_namespace' => $target->getNamespace(),
 263                                 'wl_title' => $target->getDBkey(),
 264                         ],
 265                         __METHOD__
 266                 );
 267                 $this->reuseConnection( $dbr );
 268
 269                 return $return;
 270         }
 271
 272         /**
 273          * Number of page watchers who also visited a "recent" edit
 274          *
 275          * @param LinkTarget $target
 276          * @param mixed $threshold timestamp accepted by wfTimestamp
 277          *
 278          * @return int
 279          * @throws DBUnexpectedError
 280          * @throws MWException
 281          */
 282         public function countVisitingWatchers( LinkTarget $target, $threshold ) {
 283                 $dbr = $this->getConnection( DB_SLAVE );
 284                 $visitingWatchers = (int)$dbr->selectField(
 285                         'watchlist',
 286                         'COUNT(*)',
 287                         [
 288                                 'wl_namespace' => $target->getNamespace(),
 289                                 'wl_title' => $target->getDBkey(),
 290                                 'wl_notificationtimestamp >= ' .
 291                                 $dbr->addQuotes( $dbr->timestamp( $threshold ) ) .
 292                                 ' OR wl_notificationtimestamp IS NULL'
 293                         ],
 294                         __METHOD__
 295                 );
 296                 $this->reuseConnection( $dbr );
 297
 298                 return $visitingWatchers;
 299         }
 300
 301         /**
 302          * @param LinkTarget[] $targets
 303          * @param array $options Allowed keys:
 304          *        'minimumWatchers' => int
 305          *
 306          * @return array multi dimensional like $return[$namespaceId][$titleString] = int $watchers
 307          *         All targets will be present in the result. 0 either means no watchers or the number
 308          *         of watchers was below the minimumWatchers option if passed.
 309          */
 310         public function countWatchersMultiple( array $targets, array $options = [] ) {
 311                 $dbOptions = [ 'GROUP BY' => [ 'wl_namespace', 'wl_title' ] ];
 312
 313                 $dbr = $this->getConnection( DB_SLAVE );
 314
 315                 if ( array_key_exists( 'minimumWatchers', $options ) ) {
 316                         $dbOptions['HAVING'] = 'COUNT(*) >= ' . (int)$options['minimumWatchers'];
 317                 }
 318
 319                 $lb = new LinkBatch( $targets );
 320                 $res = $dbr->select(
 321                         'watchlist',
 322                         [ 'wl_title', 'wl_namespace', 'watchers' => 'COUNT(*)' ],
 323                         [ $lb->constructSet( 'wl', $dbr ) ],
 324                         __METHOD__,
 325                         $dbOptions
 326                 );
 327
 328                 $this->reuseConnection( $dbr );
 329
 330                 $watchCounts = [];
 331                 foreach ( $targets as $linkTarget ) {
 332                         $watchCounts[$linkTarget->getNamespace()][$linkTarget->getDBkey()] = 0;
 333                 }
 334
 335                 foreach ( $res as $row ) {
 336                         $watchCounts[$row->wl_namespace][$row->wl_title] = (int)$row->watchers;
 337                 }
 338
 339                 return $watchCounts;
 340         }
 341
 342         /**
 343          * Get an item (may be cached)
 344          *
 345          * @param User $user
 346          * @param LinkTarget $target
 347          *
 348          * @return WatchedItem|false
 349          */
 350         public function getWatchedItem( User $user, LinkTarget $target ) {
 351                 if ( $user->isAnon() ) {
 352                         return false;
 353                 }
 354
 355                 $cached = $this->getCached( $user, $target );
 356                 if ( $cached ) {
 357                         return $cached;
 358                 }
 359                 return $this->loadWatchedItem( $user, $target );
 360         }
 361
 362         /**
 363          * Loads an item from the db
 364          *
 365          * @param User $user
 366          * @param LinkTarget $target
 367          *
 368          * @return WatchedItem|false
 369          */
 370         public function loadWatchedItem( User $user, LinkTarget $target ) {
 371                 // Only loggedin user can have a watchlist
 372                 if ( $user->isAnon() ) {
 373                         return false;
 374                 }
 375
 376                 $dbr = $this->getConnection( DB_SLAVE );
 377                 $row = $dbr->selectRow(
 378                         'watchlist',
 379                         'wl_notificationtimestamp',
 380                         $this->dbCond( $user, $target ),
 381                         __METHOD__
 382                 );
 383                 $this->reuseConnection( $dbr );
 384
 385                 if ( !$row ) {
 386                         return false;
 387                 }
 388
 389                 $item = new WatchedItem(
 390                         $user,
 391                         $target,
 392                         $row->wl_notificationtimestamp
 393                 );
 394                 $this->cache( $item );
 395
 396                 return $item;
 397         }
 398
 399         /**
 400          * Must be called separately for Subject & Talk namespaces
 401          *
 402          * @param User $user
 403          * @param LinkTarget $target
 404          *
 405          * @return bool
 406          */
 407         public function isWatched( User $user, LinkTarget $target ) {
 408                 return (bool)$this->getWatchedItem( $user, $target );
 409         }
 410
 411         /**
 412          * Must be called separately for Subject & Talk namespaces
 413          *
 414          * @param User $user
 415          * @param LinkTarget $target
 416          */
 417         public function addWatch( User $user, LinkTarget $target ) {
 418                 $this->addWatchBatch( [ [ $user, $target ] ] );
 419         }
 420
 421         /**
 422          * @param array[] $userTargetCombinations array of arrays containing [0] => User [1] => LinkTarget
 423          *
 424          * @return bool success
 425          */
 426         public function addWatchBatch( array $userTargetCombinations ) {
 427                 if ( $this->loadBalancer->getReadOnlyReason() !== false ) {
 428                         return false;
 429                 }
 430
 431                 $rows = [];
 432                 foreach ( $userTargetCombinations as list( $user, $target ) ) {
 433                         /**
 434                          * @var User $user
 435                          * @var LinkTarget $target
 436                          */
 437
 438                         // Only loggedin user can have a watchlist
 439                         if ( $user->isAnon() ) {
 440                                 continue;
 441                         }
 442                         $rows[] = [
 443                                 'wl_user' => $user->getId(),
 444                                 'wl_namespace' => $target->getNamespace(),
 445                                 'wl_title' => $target->getDBkey(),
 446                                 'wl_notificationtimestamp' => null,
 447                         ];
 448                         $this->uncache( $user, $target );
 449                 }
 450
 451                 if ( !$rows ) {
 452                         return false;
 453                 }
 454
 455                 $dbw = $this->getConnection( DB_MASTER );
 456                 foreach ( array_chunk( $rows, 100 ) as $toInsert ) {
 457                         // Use INSERT IGNORE to avoid overwriting the notification timestamp
 458                         // if there's already an entry for this page
 459                         $dbw->insert( 'watchlist', $toInsert, __METHOD__, 'IGNORE' );
 460                 }
 461                 $this->reuseConnection( $dbw );
 462
 463                 return true;
 464         }
 465
 466         /**
 467          * Removes the an entry for the User watching the LinkTarget
 468          * Must be called separately for Subject & Talk namespaces
 469          *
 470          * @param User $user
 471          * @param LinkTarget $target
 472          *
 473          * @return bool success
 474          * @throws DBUnexpectedError
 475          * @throws MWException
 476          */
 477         public function removeWatch( User $user, LinkTarget $target ) {
 478                 // Only logged in user can have a watchlist
 479                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 480                         return false;
 481                 }
 482
 483                 $this->uncache( $user, $target );
 484
 485                 $dbw = $this->getConnection( DB_MASTER );
 486                 $dbw->delete( 'watchlist',
 487                         [
 488                                 'wl_user' => $user->getId(),
 489                                 'wl_namespace' => $target->getNamespace(),
 490                                 'wl_title' => $target->getDBkey(),
 491                         ], __METHOD__
 492                 );
 493                 $success = (bool)$dbw->affectedRows();
 494                 $this->reuseConnection( $dbw );
 495
 496                 return $success;
 497         }
 498
 499         /**
 500          * @param User $editor The editor that triggered the update. Their notification
 501          *  timestamp will not be updated(they have already seen it)
 502          * @param LinkTarget $target The target to update timestamps for
 503          * @param string $timestamp Set the update timestamp to this value
 504          *
 505          * @return int[] Array of user IDs the timestamp has been updated for
 506          */
 507         public function updateNotificationTimestamp( User $editor, LinkTarget $target, $timestamp ) {
 508                 $dbw = $this->getConnection( DB_MASTER );
 509                 $res = $dbw->select( [ 'watchlist' ],
 510                         [ 'wl_user' ],
 511                         [
 512                                 'wl_user != ' . intval( $editor->getId() ),
 513                                 'wl_namespace' => $target->getNamespace(),
 514                                 'wl_title' => $target->getDBkey(),
 515                                 'wl_notificationtimestamp IS NULL',
 516                         ], __METHOD__
 517                 );
 518
 519                 $watchers = [];
 520                 foreach ( $res as $row ) {
 521                         $watchers[] = intval( $row->wl_user );
 522                 }
 523
 524                 if ( $watchers ) {
 525                         // Update wl_notificationtimestamp for all watching users except the editor
 526                         $fname = __METHOD__;
 527                         $dbw->onTransactionIdle(
 528                                 function () use ( $dbw, $timestamp, $watchers, $target, $fname ) {
 529                                         $dbw->update( 'watchlist',
 530                                                 [ /* SET */
 531                                                         'wl_notificationtimestamp' => $dbw->timestamp( $timestamp )
 532                                                 ], [ /* WHERE */
 533                                                         'wl_user' => $watchers,
 534                                                         'wl_namespace' => $target->getNamespace(),
 535                                                         'wl_title' => $target->getDBkey(),
 536                                                 ], $fname
 537                                         );
 538                                         $this->uncacheLinkTarget( $target );
 539                                 }
 540                         );
 541                 }
 542
 543                 $this->reuseConnection( $dbw );
 544
 545                 return $watchers;
 546         }
 547
 548         /**
 549          * Reset the notification timestamp of this entry
 550          *
 551          * @param User $user
 552          * @param Title $title
 553          * @param string $force Whether to force the write query to be executed even if the
 554          *    page is not watched or the notification timestamp is already NULL.
 555          *    'force' in order to force
 556          * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
 557          *
 558          * @return bool success
 559          */
 560         public function resetNotificationTimestamp( User $user, Title $title, $force = '', $oldid = 0 ) {
 561                 // Only loggedin user can have a watchlist
 562                 if ( $this->loadBalancer->getReadOnlyReason() !== false || $user->isAnon() ) {
 563                         return false;
 564                 }
 565
 566                 $item = null;
 567                 if ( $force != 'force' ) {
 568                         $item = $this->loadWatchedItem( $user, $title );
 569                         if ( !$item || $item->getNotificationTimestamp() === null ) {
 570                                 return false;
 571                         }
 572                 }
 573
 574                 // If the page is watched by the user (or may be watched), update the timestamp
 575                 $job = new ActivityUpdateJob(
 576                         $title,
 577                         [
 578                                 'type'      => 'updateWatchlistNotification',
 579                                 'userid'    => $user->getId(),
 580                                 'notifTime' => $this->getNotificationTimestamp( $user, $title, $item, $force, $oldid ),
 581                                 'curTime'   => time()
 582                         ]
 583                 );
 584
 585                 // Try to run this post-send
 586                 // Calls DeferredUpdates::addCallableUpdate in normal operation
 587                 call_user_func(
 588                         $this->deferredUpdatesAddCallableUpdateCallback,
 589                         function() use ( $job ) {
 590                                 $job->run();
 591                         }
 592                 );
 593
 594                 $this->uncache( $user, $title );
 595
 596                 return true;
 597         }
 598
 599         private function getNotificationTimestamp( User $user, Title $title, $item, $force, $oldid ) {
 600                 if ( !$oldid ) {
 601                         // No oldid given, assuming latest revision; clear the timestamp.
 602                         return null;
 603                 }
 604
 605                 if ( !$title->getNextRevisionID( $oldid ) ) {
 606                         // Oldid given and is the latest revision for this title; clear the timestamp.
 607                         return null;
 608                 }
 609
 610                 if ( $item === null ) {
 611                         $item = $this->loadWatchedItem( $user, $title );
 612                 }
 613
 614                 if ( !$item ) {
 615                         // This can only happen if $force is enabled.
 616                         return null;
 617                 }
 618
 619                 // Oldid given and isn't the latest; update the timestamp.
 620                 // This will result in no further notification emails being sent!
 621                 // Calls Revision::getTimestampFromId in normal operation
 622                 $notificationTimestamp = call_user_func(
 623                         $this->revisionGetTimestampFromIdCallback,
 624                         $title,
 625                         $oldid
 626                 );
 627
 628                 // We need to go one second to the future because of various strict comparisons
 629                 // throughout the codebase
 630                 $ts = new MWTimestamp( $notificationTimestamp );
 631                 $ts->timestamp->add( new DateInterval( 'PT1S' ) );
 632                 $notificationTimestamp = $ts->getTimestamp( TS_MW );
 633
 634                 if ( $notificationTimestamp < $item->getNotificationTimestamp() ) {
 635                         if ( $force != 'force' ) {
 636                                 return false;
 637                         } else {
 638                                 // This is a little silly…
 639                                 return $item->getNotificationTimestamp();
 640                         }
 641                 }
 642
 643                 return $notificationTimestamp;
 644         }
 645
 646         /**
 647          * @param User $user
 648          * @param int $unreadLimit
 649          *
 650          * @return int|bool The number of unread notifications
 651          *                  true if greater than or equal to $unreadLimit
 652          */
 653         public function countUnreadNotifications( User $user, $unreadLimit = null ) {
 654                 $queryOptions = [];
 655                 if ( $unreadLimit !== null ) {
 656                         $unreadLimit = (int)$unreadLimit;
 657                         $queryOptions['LIMIT'] = $unreadLimit;
 658                 }
 659
 660                 $dbr = $this->getConnection( DB_SLAVE );
 661                 $rowCount = $dbr->selectRowCount(
 662                         'watchlist',
 663                         '1',
 664                         [
 665                                 'wl_user' => $user->getId(),
 666                                 'wl_notificationtimestamp IS NOT NULL',
 667                         ],
 668                         __METHOD__,
 669                         $queryOptions
 670                 );
 671                 $this->reuseConnection( $dbr );
 672
 673                 if ( !isset( $unreadLimit ) ) {
 674                         return $rowCount;
 675                 }
 676
 677                 if ( $rowCount >= $unreadLimit ) {
 678                         return true;
 679                 }
 680
 681                 return $rowCount;
 682         }
 683
 684         /**
 685          * Check if the given title already is watched by the user, and if so
 686          * add a watch for the new title.
 687          *
 688          * To be used for page renames and such.
 689          *
 690          * @param LinkTarget $oldTarget
 691          * @param LinkTarget $newTarget
 692          */
 693         public function duplicateAllAssociatedEntries( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 694                 if ( !$oldTarget instanceof Title ) {
 695                         $oldTarget = Title::newFromLinkTarget( $oldTarget );
 696                 }
 697                 if ( !$newTarget instanceof Title ) {
 698                         $newTarget = Title::newFromLinkTarget( $newTarget );
 699                 }
 700
 701                 $this->duplicateEntry( $oldTarget->getSubjectPage(), $newTarget->getSubjectPage() );
 702                 $this->duplicateEntry( $oldTarget->getTalkPage(), $newTarget->getTalkPage() );
 703         }
 704
 705         /**
 706          * Check if the given title already is watched by the user, and if so
 707          * add a watch for the new title.
 708          *
 709          * To be used for page renames and such.
 710          * This must be called separately for Subject and Talk pages
 711          *
 712          * @param LinkTarget $oldTarget
 713          * @param LinkTarget $newTarget
 714          */
 715         public function duplicateEntry( LinkTarget $oldTarget, LinkTarget $newTarget ) {
 716                 $dbw = $this->getConnection( DB_MASTER );
 717
 718                 $result = $dbw->select(
 719                         'watchlist',
 720                         [ 'wl_user', 'wl_notificationtimestamp' ],
 721                         [
 722                                 'wl_namespace' => $oldTarget->getNamespace(),
 723                                 'wl_title' => $oldTarget->getDBkey(),
 724                         ],
 725                         __METHOD__,
 726                         [ 'FOR UPDATE' ]
 727                 );
 728
 729                 $newNamespace = $newTarget->getNamespace();
 730                 $newDBkey = $newTarget->getDBkey();
 731
 732                 # Construct array to replace into the watchlist
 733                 $values = [];
 734                 foreach ( $result as $row ) {
 735                         $values[] = [
 736                                 'wl_user' => $row->wl_user,
 737                                 'wl_namespace' => $newNamespace,
 738                                 'wl_title' => $newDBkey,
 739                                 'wl_notificationtimestamp' => $row->wl_notificationtimestamp,
 740                         ];
 741                 }
 742
 743                 if ( !empty( $values ) ) {
 744                         # Perform replace
 745                         # Note that multi-row replace is very efficient for MySQL but may be inefficient for
 746                         # some other DBMSes, mostly due to poor simulation by us
 747                         $dbw->replace(
 748                                 'watchlist',
 749                                 [ [ 'wl_user', 'wl_namespace', 'wl_title' ] ],
 750                                 $values,
 751                                 __METHOD__
 752                         );
 753                 }
 754
 755                 $this->reuseConnection( $dbw );
 756         }
 757
 758 }